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Lactobacilli Interfere with Streptococcus pyogenes Hemolytic Activity and Adherence to Host Epithelial Cells
Sunil D Saroj1, Lisa Maudsdotter1, Raquel Tavares1
1Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University Stockholm, Sweden.
Frontiers in Microbiology
|August 16, 2016
Summary
Certain Lactobacillus strains can inhibit Group A Streptococcus (GAS) virulence by reducing toxin production and adherence. Combinations of these beneficial bacteria show promise for preventing GAS colonization and developing new therapeutics.
Area of Science:
- Microbiology
- Immunology
- Medical Science
Background:
- Group A Streptococcus (GAS) frequently colonizes the respiratory tract, causing diseases from pharyngitis to toxic shock.
- Lactobacilli are known to colonize the respiratory tract.
- Investigating the interaction between Lactobacilli and GAS virulence is crucial for understanding host defense and developing interventions.
Purpose of the Study:
- To investigate the interference of specific Lactobacillus strains with the virulence phenotypes of Group A Streptococcus (GAS).
- To determine the effect of Lactobacillus strains on GAS hemolytic activity and adherence to host cells.
- To explore the potential of Lactobacillus-derived molecules in combating GAS infections.
Main Methods:
- Assessing the hemolytic activity of S. pyogenes S165 in the presence of different Lactobacillus strains.
- Analyzing the effect of Lactobacillus conditioned medium on the expression of the streptolysin S (SLS) operon (sag operon).
- Evaluating the inhibition of GAS adherence to host epithelial cells by individual and combined Lactobacillus species.
Main Results:
- Lactobacillus rhamnosus Kx151A1 and L. reuteri PTA-5289 inhibited GAS hemolytic activity by decreasing streptolysin S (SLS) production.
- Conditioned medium from these Lactobacillus strains down-regulated the sag operon transcription.
- All tested Lactobacillus strains inhibited initial GAS adherence, with combinations being most effective.
Conclusions:
- Lactobacillus strains can attenuate GAS virulence by reducing SLS production at the transcriptional level.
- Combinations of Lactobacillus species offer enhanced protection against GAS initial colonization of the pharyngeal mucosa.
- Lactobacillus-derived effector molecules represent a potential avenue for developing novel therapeutics against GAS infections.
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